Ecological dynamics
[Caveat: The vegetation information contained in this section and is only provisional, based on concepts, and future projects support validation through field work. *] The vegetation groupings described in this section are based on the terrestrial ecological system classification and vegetation associations developed by NatureServe (Comer et al., 2003) and localized associations provided by the New York Natural Heritage Program (Edinger et al., 2014), Maine Natural Areas Program (Gawler and Cutko, 2010), New Hampshire Natural Heritage Program (Sperduto and Nichols, 2011), and Massachusetts Division of Fisheries and Wildlife (Swain, 2020).
The Marsh Wetland Complex ecological site includes many distinctive wetland communities dominated by complex community mosaics in which diverse graminoids, herbs, and shrub species grow differently along slight changes in soil wetness. These communities are permanently saturated and seasonally inundated, allowing for the development of shallow to moderately deep organic muck over mineral soils. The following State and Transition Model (STM) is broken into separate states based on the dominant functional group, which often correlates closely with associated hydrology of a site. While occurring as stand along vegetative communities, the Marsh Wetland Complex ecological site may also serve as a successional pathway for other wooded wetland ecological sites that have been subjected to changes in hydrology. Further study is required to distinguish the relationship between hydrology and vegetation.
These are open wetlands communities in which trees and shrubs are generally absent or sparse (less than 25 percent cover) due to the long duration of inundation (seasonally in spring to summer months) and the very low availability of dissolved oxygen and minerals. Vegetation under natural conditions will vary by changes in localized hydrology and can be separated by dominant functional groups reflecting those changes under natural or anthropogenically altered conditions.
These sites are highly susceptible to altered hydrology, whether of natural or anthropogenic influences. Dams or structures that alter the long-term hydrology of a site can create these marsh complexes, depending on the amount of stagnant water and time. A forested area may become non-forested with standing dead snags reflecting the past conditions when water levels were lower, shifting the understory composition to graminoid or forb dominance. These dammed areas will often be maintained by a beaver population in the area and can persist for extended periods of time. Upon abandonment or removal of a beaver population or dam, ponded areas will drain and revert to a graminoid meadow which can resist succession to a shrubland or forested community despite a proximity to active seed sources or though relict seedbeds due to waterlogged soils (Terwilliger and Pastor 1999). In areas of natural geographic depressions where beaver influence in minimal, persistence of one community may occur for decades until acted upon by a natural or anthropogenic influence.
Introduction and persistence of exotic and non-native grasses and grass-like plants are common throughout much of New England, and can form dense mats that exclude native plants, alter ecosystems functions, and provide little to no value as wildlife food or cover (Destefano 2013). Native grass-like monocultures, such as cattail marshes, are in part the result of past hydrologic manipulation and increased fertility associated with agricultural runoff, which can reduce the diversity of other wetland types and wildlife species that rely on them. Areas that have been chemically or mechanically disturbed by human activity may allow for the establishment of monocultures of reed marshes (Phalaris & Phragmites spp.) in which few or no other vascular plants can survive, displacing native vegetation over time.
While fire is not commonly known as a driver in New England, especially in wetland communities, replacement severity fires (causing >75% kill or top kill of the upper canopy layer) for northeastern shrub and herbaceous wetlands may occur at intervals of approximately 780 years or during periods of extreme drought (U.S. Department of Agriculture, Forest Service, Missoula Fire Sciences Laboratory 2012). Removal of organic matter from fire may prevent seed germination and act as a driver to lower the soil surface, causing localized increases in hydrology and shifting vegetative communities.
While drainage of this site has yet to be observed, some sedge and wet meadows have been used for hay fields and kept in an early successional stage by periodic mowing when fields are dry (Thompson and Sorenson 2019). This hay is often coarse and unpalatable to cows and is used as bedding. These sites are unsuited for agriculture.
State 1
Sedge and Wet Meadows
Figure 7. Typical Sedge/Wet Meadow of the Marsh Wetland Complex site. Diverse graminoids are dominant, shrubs are low and sparse individuals, and trees are absent. Photo taken April 2025, West Danville, VT.
These are graminoid dominant wetlands comprised most often of sedges and grasses in a monotypic or mixed stand of often greater than 50 percent cover. Forbs will often be present in lower amounts and locally abundant but not dominant. Trees, shrubs, and other woody species will often be sparse to absent, occurring as stunted individuals found on microhighs created from past tip ups. The ground cover typically consists of herbaceous litter mixed with bryophytes, which is usually sparse but may occasionally reach over 50 percent cover. The vegetation is often firmly rooted in the substrate and will not form floating mats when inundated unlike similar Sphagnum bog sites. Standing water may be present ranging from only the beginning, or throughout much of the growing season, depending on the site and the years precipitation, with the soil remaining saturated even when water levels drop. Changes in community phases will often be dependent on slight changes in hydroperiod and the presence or absence of a viable seedbank. Further study is needed to assess the potential drivers between community phases and will be left blank until it can be assessed. The absence of community pathway arrows does not indicate these communities can transition to one another and will only exist as standalone stable communities but rather is left blank until data becomes available explaining such a transition.
These community types correlate with LandFire’s CES201.582 “Laurentian-Acadian Wet Meadow-Shrub Swamp” classifications.
Dominant plant species
-
upright sedge (Carex stricta), grass
-
blister sedge (Carex vesicaria), grass
-
Northwest Territory sedge (Carex utriculata), grass
-
bluejoint (Calamagrostis canadensis), grass
-
reed canarygrass (Phalaris arundinacea), grass
-
woolgrass (Scirpus cyperinus), grass
-
panicled bulrush (Scirpus microcarpus), grass
-
green bulrush (Scirpus atrovirens), grass
-
three-way sedge (Dulichium arundinaceum), grass
-
swamp milkweed (Asclepias incarnata), other herbaceous
-
eastern marsh fern (Thelypteris palustris), other herbaceous
-
marsh bellflower (Campanula aparinoides), other herbaceous
-
harlequin blueflag (Iris versicolor), other herbaceous
-
purple marshlocks (Comarum palustre), other herbaceous
-
spotted joe pye weed (Eutrochium maculatum), other herbaceous
Community 1.1
Sedge (Carex spp.) Dominated Wet Meadow
These are sedge dominated meadows in which the genus Carex is the primary species. Herbaceous species, particularly upright sedge (Carex stricta) in its tussock form, are dominant. Shrubs will typically be sparse but may have up to 25 percent cover. Trees are absent. Bryophyte cover is usually sparse but may reach over 50 percent cover. The tussock growth form in these sedge meadows form the characteristic high raised mounds unique to this site. While one species of sedge is often dominant, other sedges may be dominant at other sites or mix to create a heterogeneous stand of sedges, mixed with lower number of grasses and forbs. This will often grade into mixed grasses and sedge wet meadows (Phase 1.2) but is distinctive by its dominance of sedges (>50%) and minor grass dominance (<50%).
Within the Northeast US, this community type correlates to Maine’s “Sedge Meadow” concept (Gawler and Cutko 2010), New Hampshire’s “Tall Graminoid Emergent Marsh – Tussock Sedge Variant” concept (Sperduto and Nichols 2012), New York’s “Sedge Meadow” concept (Edinger et al. 2014), and Vermont’s “Sedge Meadow” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes ‘Carex stricta – Carex vesicaria Wet Meadow' Association (CEGL006412).
Forest understory. In addition to the various graminoids listed, less dominant forbs and shrubs may be present. Shrub species may include grey alder (Alnus incana), sweetgale (Myrica gale), winterberry (Ilex verticillata), leatherleaf (Chamaedaphne calyculata), and white meadowsweet (Spiraea alba). Additional forbs include swamp milkweed (Asclepias incarnata), marsh fern (Thelypteris palustris), spotted joe-pye weed (Eutrochium maculatum), marsh bellflower (Campanula aparinoides), royal fern (Osmunda regalis), marsh cinquefoil (Comarum palustre), swamp candles (Lysimachia terrestris), American angelica (Angelica atropurpurea), common boneset (Eupatorium perfoliatum), American bugelweed (Lycopus americanus), swamp smartweed (Polygonum hydropiperoides), bluntleaf bedstraw (Galium obtusum), arrow-leaved tearthumb (Polygonum sagittatum), and stiff marsh bedstraw (Galium tinctorium), to name a few.
Dominant plant species
-
upright sedge (Carex stricta), grass
-
blister sedge (Carex vesicaria), grass
-
Northwest Territory sedge (Carex utriculata), grass
-
prickly bog sedge (Carex atlantica), grass
-
silvery sedge (Carex canescens), grass
-
longhair sedge (Carex comosa), grass
-
northern long sedge (Carex folliculata), grass
-
broom sedge (Carex scoparia), grass
-
awlfruit sedge (Carex stipata), grass
-
fox sedge (Carex vulpinoidea), grass
-
bluejoint (Calamagrostis canadensis), grass
-
common rush (Juncus effusus), grass
-
rattlesnake mannagrass (Glyceria canadensis), grass
-
three-way sedge (Dulichium arundinaceum), grass
-
rice cutgrass (Leersia oryzoides), grass
-
woolgrass (Scirpus cyperinus), grass
-
Magellan's sphagnum (Sphagnum magellanicum), other herbaceous
-
Girgensohn's sphagnum (Sphagnum girgensohnii), other herbaceous
-
prairie sphagnum (Sphagnum palustre), other herbaceous
-
drepanocladus moss (Drepanocladus aduncus), other herbaceous
Community 1.2
Bluejoint (Calamagrostis canadensis) - Sedge (Carex spp.) Wet Meadow
These are mixed grasses and sedge meadows in which the genus Calamagrostis and Carex are the dominant species. Graminoid cover is typically dense and can form hummocky microtopography and is dominated by bluejoint grass (Calamagrostis canadensis) in pure stands or mixed with sedges (Carex spp.). This will often grade into sedge dominated wet meadows (Phase 1.1) but is distinctive by its dominance of grasses (>50%) and minor sedge dominance (<50%). Forbs may be locally abundant but will often be composed of a small total amount. Shrubs may be present in small amounts and will often be scattered. Trees are absent.
Within the Northeast US, this community type correlates to Maine’s “Tall Grass Meadow” concept (Gawler and Cutko 2010), New Hampshire’s “Northern Medium Sedge Meadow Marsh” concept (Sperduto and Nichols 2012), New York’s “Shallow Emergent Marsh” concept (Edinger et al. 2014), Massachusetts “Shallow Emergent Marsh” concept (Swain 2020) and Vermont’s “Shallow Emergent Marsh” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes 'Calamagrostis canadensis – Carex spp. Laurentian-Acadian Wet Meadow' Association (CEGL005448).
Forest understory. In addition to the various graminoids listed, less dominant forbs and shrubs may be present. Shrub species may include possumhaw viburnum (Viburnum nudum), arrowwood viburnum (Viburnum dentatum), white meadowsweet (Spiraea alba), silky dogwood (Cornus amomum), grey alder (Alnus incana), or smooth alder (Alnus serrulate). Additional forbs include marsh bellflower (Campanula aparinoides), bog willowherb (Epilobium leptophyllum), spotted joe-pye weed (Eutrochium maculatum (= Eupatorium maculatum)), common boneset (Eupatorium perfoliatum), northern blue flag iris (Iris versicolor), water smartweed (Polygonum amphibium), and marsh cinquefoil (Comarum palustre (= Potentilla palustris)), to name a few.
Dominant plant species
-
bluejoint (Calamagrostis canadensis), grass
-
water sedge (Carex aquatilis), grass
-
hairy sedge (Carex lacustris), grass
-
beaked sedge (Carex rostrata), grass
-
upright sedge (Carex stricta), grass
-
woollyfruit sedge (Carex lasiocarpa), grass
-
redtop (Agrostis gigantea), grass
-
American mannagrass (Glyceria grandis), grass
-
fowl bluegrass (Poa palustris), grass
-
Canada bluegrass (Poa compressa), grass
-
woolgrass (Scirpus cyperinus), grass
Community 1.3
Reed Canary Grass (Phalaris arundinacea) Marsh
These are graminoid dominant stands in which the native reed canarygrass (Phalaris arundinacea) forms monocultures or is associated with other graminoids such as bluejoint (Calamagrostis canadensis). Forbs will often be sparse but occasional stands may have a mixture of forbs equaling the graminoid cover. Shrubs may be present in small amounts and will often be scattered. Trees are absent.
Within the Northeast US, this community type correlates to New Hampshire’s “Tall Graminoid Emergent Marsh – Reed Canary Grass Variant” concept (Sperduto and Nichols 2012) and Massachusetts “Shallow Emergent Marsh” concept (Swain 2020). This correlates with NatureServes ‘Phalaris arundinacea Eastern Ruderal Marsh' Association (CEGL006044).
Forest understory. In addition to the various graminoids listed, less dominant forbs and shrubs may be present. Shrub species may include possumhaw viburnum (Viburnum nudum), arrowwood viburnum (Viburnum dentatum), willow (Salix spp.), grey alder (Alnus incana), or smooth alder (Alnus serrulate). Additional forbs include wild mint (Mentha arvensis) and purple loosestrife (Lythrum salicaria), to name a few.
Community 1.4
Woolgrass (Scirpus spp.) Wet Meadow
These are graminoid dominant meadows in which the genus Scirpus is the dominant species. Graminoid cover is typically dense and consist of one or more species of Scirpus. Forbs and other grasses will be present in lower amounts. Shrubs and trees are generally absent.
Within the Northeast US, this community type correlates to Maine’s “Grassy Shrub Marsh” concept (Gawler and Cutko 2010), New Hampshire’s “Tall Graminoid Emergent Marsh – Bulrush Variant” concept (Sperduto and Nichols 2012), New York’s “Shallow Emergent Marsh” concept (Edinger et al. 2014) and Massachusetts “Deep Emergent Marsh” concept (Swain 2020. This correlates with NatureServes 'Scirpus cyperinus Wet Meadow' Association (CEGL006349).
Community 1.5
Bluejoint (Calamagrostis canadensis) – Bulrush (Scirpus spp.) – Sedge (Carex spp.) Wet Meadow
These are mixed composition wet meadows. The vegetation is dominated by graminoids or graminoids mixed with shrubs, the latter of which can range up to 50%, but will always be exceeded by graminoid cover. In many cases, shrubs are absent. The herbaceous layer is well developed and often greater than 40% cover and up to nearly 100% cover. Bryophyte cover is highly variable. This will often grade into sedge dominated (1.1) and mixed graminoid – sedge wet meadows (1.2) but is distinctive by not being almost monotypically dominated by one species of grass or sedge.
Within the Northeast US, this community type correlates to New Hampshire’s “Tall Graminoid Emergent Marsh – Bluejoint Variant” concept (Sperduto and Nichols 2012), New York’s “Shallow Emergent Marsh” concept (Edinger et al. 2014) and Vermont’s “Shallow Emergent Marsh” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes 'Calamagrostis canadensis – Scirpus spp. – Dulichium arundinaceum Wet Meadow' Association (CEGL006519).
Forest understory. In addition to the various graminoids listed, less dominant forbs and shrubs may be present. Shrub species may include white meadowsweet (Spiraea alba), willow (Salix spp.), grey alder (Alnus incana), smooth alder (Alnus serrulata), buttonbush (Cephalanthus occidentalis), leatherleaf (Chamaedaphne calyculata), sweetgale (Myrica gale), pale st. john's-wort (Hypericum ellipticum), winterberry (Ilex verticillata), and blueberry (Vaccinium spp.). Additional forbs include northern blue flag iris (Iris versicolor), (Triadenum fraseri), swamp candles (Lysimachia terrestris), sensitive fern (Onoclea sensibilis), and royal fern (Osmunda regalis), to name a few.
Dominant plant species
-
bluejoint (Calamagrostis canadensis), grass
-
woolgrass (Scirpus cyperinus), grass
-
woodland bulrush (Scirpus expansus), grass
-
green bulrush (Scirpus atrovirens), grass
-
upright sedge (Carex stricta), grass
-
Northwest Territory sedge (Carex utriculata), grass
-
shallow sedge (Carex lurida), grass
-
false hop sedge (Carex lupuliformis), grass
-
hop sedge (Carex lupulina), grass
-
hairy sedge (Carex lacustris), grass
-
three-way sedge (Dulichium arundinaceum), grass
-
calamus (Acorus calamus), grass
-
redtop (Agrostis gigantea), grass
-
rattlesnake mannagrass (Glyceria canadensis), grass
-
American mannagrass (Glyceria grandis), grass
-
Canadian rush (Juncus canadensis), grass
-
reed canarygrass (Phalaris arundinacea), grass
-
fowl bluegrass (Poa palustris), grass
State 2
Shrub Swamps
Figure 8. Typical Alder Swamp of the Marsh Wetland Complex site. Alnus serrulata is the dominant cover. Photo taken April 2025 (before leaf out), West Danville, VT.
These are wetlands of shrub dominance, often reflecting slightly lower seasonal high-water tables or decreased long-term hydroperiods. In naturally occurring areas shrubs will tend to dominant the higher perimeter and mounds within the graminoid marsh site. These shrubs will often be tall in stature (6 to 26 feet [2 to 8 meters]) and may be moderately open to dense in canopy cover (at least 50 percent cover). Scattered trees may be present, with graminoids and forbs representing the surrounding marsh community locally abundant in canopy openings. A groundcover of mosses is typically present. In areas where shrub swamps are part of a successional pathway for a wooded wetland, the dense canopy cover may delay succession to forested conditions and perpetuate shrubland conditions.
These community types correlate with LandFire’s CES201.582 “Laurentian-Acadian Wet Meadow-Shrub Swamp” classifications.
Community 2.1
Alder (Alnus spp.) Shrub Swamp
Figure 9. Typical Alder Swamp of the Marsh Wetland Complex site. Alnus serrulata is the dominant cover and tall (~9 feet [3 meters]). Photo taken April 2025 (before leaf out), West Danville, VT.
These are shrub dominated swamps and will often be found in a steady state or as along a successional pathway to another community type. The vegetation is dominated by tall shrubs, most often speckled alder (Alnus incana) forming dense, nearly impenetrable thickets. Where alder is not dominant, other wetland shrubs can be found. The herbaceous layer contains forms and graminoids reflective of the surrounding marsh if seen as an inclusion or the relict marsh if seen as a successional community. Then ground layer will often be highly variable depending on the presence or absence of canopy openings, with herbaceous species being denser in canopy gaps.
If seen as a transitional community along a successional path from a previously flooded beaver meadow back to a forested wetland, scattered stunted trees and saplings may be found in the alder stands.
Within the Northeast US, this community type correlates to Maine’s “Alder Thicket” concept (Gawler and Cutko 2010), New Hampshire’s “Speckled Alder Wooded Fen” concept (Sperduto and Nichols 2012), New York’s “Shrub Swamp” concept (Edinger et al. 2014) and Vermont’s “Alder Swamp” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes ‘Alnus incana Shrub Swamp' Association (CEGL006839).
Forest overstory. If observed as a transitional pathway to a forested wetland (R143X00Y302 - Mucky Swamp), immature trees such as red maple (Acer rubrum), black ash (Fraxinus nigra), northern white cedar (Thuja occidentalis), or black spruce (Picea mariana) may be present but not dominant (<25% canopy cover).
Forest understory. In addition to the shrub species listed, less dominant forbs and graminoids may be present. Graminoids include bluejoint (Calamagrostis canadensis), upright sedge (Carex stricta), prairie sedge (Carex prairea), three-seeded sedge (Carex trisperma), and dark green bulrush (Scirpus atrovirens). Additional forbs include tall flat-topped white aster (Doellingeria umbellata (= Aster umbellatus)), spotted joe-pye weed (Eutrochium maculatum (= Eupatorium maculatum)), jewelweed (Impatiens capensis), northern bugelweed (Lycopus uniflorus), sensitive fern (Onoclea sensibilis), cinnamon fern (Osmunda cinnamomea), dwarf raspberry (Rubus pubescens), marsh fern (Thelypteris palustris), and violets (Viola spp.) to name a few.
State 3
Freshwater Emergents and Open Water
These are wetlands of emergent vegetation and areas of open water, often reflecting slightly higher seasonal high-water tables or increased long-term hydroperiods. Hydrologic regimes are often the longest in this state, with long-term or permanent inundation influencing the development of freshwater emergent species. Organic soils are often deepest in these states but may often include shallow organics or high organic content mineral soils. These communities will often form near monocultures and be so dense that germination of other species is limited.
These community types correlate with LandFire’s CES201.594 “Laurentian-Acadian Freshwater Marsh” classifications.
Community 3.1
Cattail (Typha spp.) Marsh
These are tall emergent marshes dominated by cattail (Typha spp.). Shrubs will often be scattered to absent. Trees are absent. Bryophyte cover varies depending on depth and duration of inundation.
Within the Northeast US, this community type correlates to Maine’s “Cattail Marsh” concept (Gawler and Cutko 2010), New Hampshire’s “Cattail Marsh” concept (Sperduto and Nichols 2012), New York’s “Shallow Emergent Marsh” concept (Edinger et al. 2014) and Vermont’s “Cattail Marsh” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes ‘Typha (angustifolia, latifolia) – (Schoenoplectus spp.) Eastern Marsh' Association (CEGL006153).
Forest understory. Other locally abundant grasses and forbs may be present depending on the depth and duration of inundation and density of cattails. Additional graminoids may include sedges, such as water sedge (Carex aquatilis), shallow sedge (Carex lurida), woolly sedge (Carex pellita), beaked sedge (Carex rostrata), upright sedge (Carex stricta), woolgrass (Scirpus cyperinus), and bulrushes, such as chairmaker's bulrush (Schoenoplectus americanus) and hard-stem bulrush (Schoenoplectus acutus), occur along with patchy grasses, such as bluejoint (Calamagrostis canadensis). Additional forbs may include swamp milkweed (Asclepias incarnata), water arum (Calla palustris), jewelweed (Impatiens capensis), sensitive fern (Onoclea sensibilis), broadleaf arrowhead (Sagittaria latifolia), blue skullcap (Scutellaria lateriflora), giant bur-reed (Sparganium eurycarpum), eastern skunk cabbage (Symplocarpus foetidus), marsh fern (Thelypteris palustris), and blue verbain (Verbena hastata), to name a few.
Community 3.2
Leafy Forb Marsh
The vegetation of these marshes is broadly defined and can considerably vary in the dominant vegetation present from one marsh to another but is characterized by leafy forbs and freshwater emergent species. These are permanently inundated systems in all but the driest conditions, occurring in moderately deep standing water (at least 6 inches to 3 feet [0.1 to 1 meter]). Dominant vegetation will often result from competition, with clonal species becoming established and excluding most other species.
Within the Northeast US, this community type correlates to Maine’s “Pickerelweed Marsh” concept (Gawler and Cutko 2010), New Hampshire’s “Deep Emergent – Aquatic Bed / Medium Depth Emergent Marsh” concept (Sperduto and Nichols 2012), New York’s “Deep Emergent Marsh” concept (Edinger et al. 2014) and Vermont’s “Deep Broadleaf Marsh” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes ‘Pontederia cordata – Peltandra virginica – Sagittaria latifolia Marsh' Association (CEGL006191).
Dominant plant species
-
pickerelweed (Pontederia cordata), other herbaceous
-
broadleaf arrowhead (Sagittaria latifolia), other herbaceous
-
green arrow arum (Peltandra virginica), other herbaceous
-
bur-reed (Sparganium), other herbaceous
-
common spikerush (Eleocharis palustris), other herbaceous
-
softstem bulrush (Schoenoplectus tabernaemontani), other herbaceous
-
calamus (Acorus calamus), other herbaceous
-
yellow pond-lily (Nuphar lutea), other herbaceous
-
American white waterlily (Nymphaea odorata), other herbaceous
-
hemlock waterparsnip (Sium suave), other herbaceous
-
coon's tail (Ceratophyllum demersum), other herbaceous
-
common bladderwort (Utricularia macrorhiza), other herbaceous
Community 3.3
Bulrush (Schoenoplectus spp.) Deepwater Marsh
These are freshwater marshes consisting of monotypic stands of bulrush (Schoenplectus spp.). These are permanently inundated systems in all but the driest conditions, occurring in deep water (usually 1 to 3 feet [0.4 to 1 meter]) and will often grade into open water systems in areas of deeper more exposed water bodies (lakes shores, large marsh systems) or into freshwater emergent species in more sheltered water bodies (smaller pond shores, bays). Associated forbs and graminoids will often be present in smaller amounts but not dominant.
Within the Northeast US, this community type correlates to Maine’s “Bulrush Bed” concept (Gawler and Cutko 2010), New Hampshire’s “Tall Graminoid Emergent Marsh – Bulrush Variant” concept (Sperduto and Nichols 2012), New York’s “Deep Emergent Marsh” concept (Edinger et al. 2014) and Vermont’s “Deep Bulrush Marsh” concept (Thompson, Sorenson, and Zaino 2019). This correlates with NatureServes ‘Schoenoplectus (tabernaemontani, acutus) Eastern Marsh' Association (CEGL006275).
Forest understory. Other locally abundant grasses and forbs may be present depending on the depth and duration of inundation and density of bulrushes. Additional graminoids may include sedges, such as water sedge (Carex aquatilis), woolly sedge (Carex pellita), common beaked sedge (Carex utriculata), and woolgrass (Scirpus cyperinus). Additional forbs may include swamp milkweed (Asclepias incarnata), jewelweed (Impatiens capensis), broadleaf arrowhead (Sagittaria latifolia), blue skullcap (Scutellaria lateriflora), marsh fern (Thelypteris palustris), broadleaf cattail (Typha latifolia), pickerelweed (Pontederia cordata), river bulrush (Bolboschoenus fluviatilis), marsh seedbox (Ludwigia palustris), and blue verbain (Verbena hastata), to name a few. Floating-leaved and submerged plants (such as pondweeds [Potamogeton spp.], Canadian waterweed [Elodea canadensis], hornwort [Ceratophyllum spp.]) may be scattered among the emergent plants.
Community 3.4
Open Water
This phase describes the impact of increased hydroperiods the results in a permanently inundated condition in which rooted floating or emergent species cannot persist.
State 4
Non-Native or Exotic Species Dominance
These are wetlands in which non-native or exotic invasive species have been locally introduced and occur as a monoculture or as a mixed association with other native species but comprising more than 50 percent cover.
Community 4.1
Phragmites – Reed Marsh
This wetland phase is often seen in semipermanent inundated marshes, ditches, impoundments, etc. that have been disturbed by human activity. The vegetation is variable but will often consist of phragmites invading natural or semi-natural communities. Once established, this community can exclude other species from growing.
Within the Northeast US, this community type correlates with NatureServes ‘Phragmites australis ssp. australis Eastern Ruderal Marsh' Association (CEGL004141).
Community 4.2
Water Chestnut – Standing Water
This wetland phase is often seen in more permanently inundated marshes, a result of anthropogenic or natural damming. Water chestnut is the dominant floating emergent plant in these communities, colonizing deep marshes and excluding native species.
Dominant plant species
-
water chestnut (Trapa natans), other herbaceous
Transition T1A
State 1 to 2
This can occur through decreases in the long-term hydroperiod, causing the seasonal high water table to lower and allow the establishment of shrub dominance. This may occur naturally through beaver dam removal or anthropogenically through landscape level drainage or anthropogenic dam removal.
Transition T1B
State 1 to 3
This can occur through increases in the long-term hydroperiod, causing the seasonal high water table to increase, potentially causing permanent inundation, and allow the establishment of non-persistent freshwater emergents. This may occur naturally through beaver dam creation or anthropogenically through anthropogenic dam installation.
Transition T1C
State 1 to 4
This may occur through changes in the long-term hydroperiod as well as changes in nutrient loads to the system. This is often a result of anthropogenic disturbance.
Transition T2A
State 2 to 1
This can occur through increases in the long-term hydroperiod, causing the seasonal high water table to increase, killing the existing shrubs, and allow the establishment of graminoid. This may occur naturally through beaver dam creation or anthropogenically through anthropogenic dam installation. Mechanical, biological, or chemical removal of shrubs may occur as well.
Transition T2B
State 2 to 3
This can occur through increases in the long-term hydroperiod, causing the seasonal high water table to increase, killing the existing shrubs, and allow the establishment of freshwater non-persistent emergents. This may occur naturally through beaver dam creation or anthropogenically through anthropogenic dam installation.
Transition T2C
State 2 to 4
This may occur through changes in the long-term hydroperiod as well as changes in nutrient loads to the system. This is often a result of anthropogenic disturbance.
Transition T3A
State 3 to 1
This can occur through decreases in the long-term hydroperiod, causing the seasonal high water table to low, removing the hydroperiod needed for freshwater emergent dominance, and allow the establishment of graminoids. This may occur naturally through beaver dam removal or anthropogenically through landscape level drainage or anthropogenic dam removal. Seeding of native graminoids may be needed, depending on the duration of the sites permanent inundation (i.e. a depleted seedbank).
Transition T3B
State 3 to 4
This may occur through changes in the long-term hydroperiod as well as changes in nutrient loads to the system. This is often a result of anthropogenic disturbance.
Restoration pathway R4A
State 4 to 1
This may occur through the use of chemical, biological, or mechanic treatments that removes non-native and exotic species, allowing for the reestablishment of native grasses, forbs, and shrubs. Restoration may require extensive time and money, and there is no guarantee it may work. Coordination with your local NRCS office to manage noxious and exotic species is recommended.
Restoration pathway R4B
State 4 to 2
This may occur through the use of chemical, biological, or mechanic treatments that removes non-native and exotic species, allowing for the reestablishment of native grasses, forbs, and shrubs. Restoration may require extensive time and money, and there is no guarantee it may work. Coordination with your local NRCS office to manage noxious and exotic species is recommended.
Restoration pathway R4C
State 4 to 3
This may occur through the use of chemical, biological, or mechanic treatments that removes non-native and exotic species, allowing for the reestablishment of native grasses, forbs, and shrubs. Restoration may require extensive time and money, and there is no guarantee it may work. Coordination with your local NRCS office to manage noxious and exotic species is recommended.
